Mark Twain once said that a lie can travel halfway round the world before the truth can put its socks on. Now, thanks to the internet, a lie can travel round the world, head home, take a dump, watch the entire Lord Of The Rings trilogy on DVD, make supper and die of old age before the truth has opened an eyelid. It's not Twain's fault. In his day the internet was made of string.

Chinese whispers spread online faster than any computer virus. I know this better than most because I was at the centre of one a few years ago, when I ended a Screen Burn column by recycling a very old tasteless joke (a variant of a graffiti I first saw during the Thatcher years), and within minutes half the internet seemed convinced the Guardian was officially calling for assassination.

My inbox overflowed with blood-curdling death threats, and it was all very unfunny indeed - a bit like recounting a rude joke at a dinner party, only to be told you hadn't recounted a joke at all, but molested the host's children, and suddenly everyone was punching you and you weren't going to get any pudding. I've had better weekends.

Incidentally, in case the entire internet is reading, it seems prudent at this point to unequivocally state that I've never wanted to see ANYONE murdered, injured, or even lightly bruised. Not even Mac owners, and frankly they're pushing it.

As anyone who read the original column will know, I'm not a huge fan of Bush. He's a dangerous idiot who's dragged America's name into the mud, and crapped all over it, grinning as he does so. As for Americans themselves, I can honestly say I've never met one I didn't like. Maybe I'm shallow, maybe it's the accents. But really - every single one of them: lovely.

So, having established that a) I don't like Bush but b) I love Americans, it's time for a third revelation - namely c) I don't believe 9/11 was an inside job orchestrated by the Bush administration. Which is a pity, because I love a good conspiracy theory, and that's a humdinger.

Thing is, people like me will eventually be in the minority if the Chinese whisperers have their way. I'd like to think tomorrow's excellent documentary 9/11: The Conspiracy Files (Sun, 9pm, BBC2) will redress the balance - but I doubt it, since the story it tells (ie the real one) isn't half as exciting as the other story doing the rounds (ie the bullshit cuckooland version).

In cool, measured tones it steadily dismantles the Loose Change conspiracy theory until there's nothing left to see besides a slightly snotty young director and a few unhinged talking heads. No rational person could watch this and come away thinking otherwise.

But whoops: people aren't rational. They believe what they want to believe, and when evidence mounts to the contrary, dig their heels in and refuse to change their minds, like dogs that won't be dragged through a doorway. Sometimes the sheer pressure of all that stubbornness causes them to lose their senses completely and become creationists, at which point they're beyond help.

But there's still hope for the 9/11 conspiracy theorists. Their hearts are still in the right place, even if their brains have fluttered off to spaceland. One day they'll return, like butterflies, and all will be well.

Here's what really happened on 9/11. A terrible crime was committed by a group of determined terrorists. Appalling mistakes were made both before and after the terrible crime. The terrible crime was capitalized upon. The world was shit before the terrible crime, and got steadily shittier afterwards. That's it! So please, please, stop pissing your pants about controlled demolitions and the like - you're wrong. You're wrong! And it's OK to be wrong. You can still distrust or even hate the government. But on this one? You're wrong. And continuing to bang on about it isn't heroic, it's embarrassing. The rest of the world isn't asleep. You're just dreaming out loud.